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ASI Mac Motor Documentation and Purchase Guide

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    Originally posted by brenhan View Post
    I just ordered this motor to build my own wheel. can anyone who has the tools for this measure the center to center flange spacing between the left and right sides, and also the flange diameter? I cant see that this is listed on the diagram anywhere
    I assume that you are calculating spoke length. If you do it as carefully as possible, you can use a metric scale or measuring tape for these values. If this were me, I would buy a metric scale for the occasion.

    I just bought the one in the link as a result of reading your post, although it is coming from Hong Kong. In my search, I saw a lot of shorter and cheaper metric scales from domestic sources.

    You may know that the margin of error for spoke length is 1mm either way. I have always measured carefully (using either values published by the manufacturer, digital calipers or a metric measuring tape) and never had to reorder longer or shorter spokes.

    I was pretty alarmed that different online spoke calculators provided with identical input provided different spoke length results. I used the average of these different values. What online spoke calculator do you like?

    Are you using a single cross pattern? Are you going to have the spokes touch one another where they cross? That's what I do, even though the spokes bend a little near the spoke threads.

    I always use Wheelsmith Spoke Prep. I like that stuff.

    I also put some oil on the rim where the nipple seats.

    I also use my tensiometer extensively.
    Last edited by commuter ebikes; 09-02-2018, 08:34 PM.


      I just recieved the Lunacycle ASI/Mac Motor setup for my Greenspeed trike. Already had a cheap chinese no name kit on there for quite a few years but the controller smoked a couple of months ago on a really hot day. Got a 1500 watt controller and with a Luna 52v 20Ah Panasonic PF it proceeded to tear something up internally, I suspect the one way clutch as the gears look fine. Put another spare motor on it and did the same thing... ie. don't nitrous a worn out stock 305.

      The ASI/Mac setup in a rear wheel with same battery worked laid out, but when I went to route the half throttle with key and voltage gauge under the bike the connector shell fell off the 2 wires and the orange wire (wire on that one was a bad crimp and that wire fell out of the terminal terminal which stayed in the connector. We put the connectors back together and now the throttle key switch appears to work and the voltage gauge works, but throttle does nothing to spin the wheel. No instructions or wiring diagram was in the box so there is the possibility that the two wire connector pins from the throttle got flipped, but no idea how to test without a diagram. Any help?



      Anyone using the throttle with the voltage read out? The key switch shuts off power to the motor but the voltage continues to display when switch is off. This eventually runs down the battery unless you disconnect it--seems weird, unless I'm missing something? thanks for any insights, pete


      • paxtana
        paxtana commented
        Editing a comment
        I don't know about the half twist but on the thumb there are three positions you can put the key switch in, and only one of which turns off the voltage readout fully. It is possible this may be the issue you are seeing.

      • badrab
        badrab commented
        Editing a comment
        Thanks for the suggestion, but nope, two position switch with both positions leaving voltage display on. Also note that Luna product page states that:

        "Convenient push button on/off power switch"

        No such switch that I can see...anyway seems odd to have to wire in another switch to shut off battery...

      I want to convert my Trek T900 Tandem to electric assist for my wife and I. I am doing the homework to choose between a BBSHD, a rear hub like the MAC described here, or to pass on conversion if there isn't a feasible and elegant solution. The bike has 26" wheels and 68mm BBs. Is a rear hub MAC motor (12T) available now, and would it perform like the BBSHD as the article says for a 400 lb. fully loaded tandem? Our riding style is on paved rail trails - 15 - 18 mph, or slower on hardpacked gravel roads and trails. Would the riding experience, speed, and range of these motors be comparable? The BSSHD is known for torque and performance, but the simpler installation of the rear hub is attractive if performance and riding experience is comparable. Thanks in advance for your input.


      • paxtana
        paxtana commented
        Editing a comment
        The low end torque is roughly comparable yes, though it is not as versatile as something that can be downshifted. 12t is also sold out so unfortunately that would not be an option at this time.

      I wouldn't recommend a BBSHD for your application. IMO the BBSHD works best when you need considerable gear reduction capability like riding off road where speeds can be very slow to pretty fast. The biggest drawback with the BBSHD is that all the power goes thru the bike's drivetrain...i.e. chain and sprockets which wears them faster than when a human is pedaling due to the increased power that is transmitted. Great motor when used appropriately.

      A hub motor doesn't use the bike's chain or sprockets...the power is transmitted directly from the motor to the wheel. They are great for reliability and low maintenance. The windings of the motor, the voltage of your battery, and the diameter of your wheel will determine your speed...I have a 12T MAC in a 27.5 rim with a 27.5x3.25 Vee tire (742mm OD) and run it with a 14s battery...when the battery is charged to 54.9 volts, my top speed is about 25 mph. The problem with the MAC is that it does not cool very well because there is an air gap between the motor and the housing. I plugged some of your parameters into the Grin Tech motor simulator: and if you run a 12T MAC on 36 volts and a 26" tire, the top speed is about 17 mph...and running the MAC wide open produces less heat than the same speed at partial throttle, just more efficient. I'd set it up so you can use a throttle to apply the assist and then you could use it if needed but it wouldn't be assisting all the time.

      A hub motor like a Crystalyte or similar is going to have a higher top speed than the MAC which has internal gears to reduce the output shaft speed but a non geared hub motor will also cool a lot better than the MAC.

      Hope this helps a little.


        I've been enjoying my setup on my recumbent trike, but the ergonomics of having twist shifters and the half twist throttle sucked, so I have upgraded from a 7 speed freewheel to a 10 speed Sunrace freewheel, and went from Shimano twist grip shifters to Microshift bar end shifters. Bought a Terracycle mount that adapts to the bar end shifter so I could mount a thumb throttle because the half twist throttle with the key and display is hard to use and hits my thigh. Ordered up a thumb throttle without a key or voltage display and was a bit surprised to find that both the two wire and three wire connector for the half twist throttle are required, I expected to just use the three wire connector thinking the two wire connector was for the voltage display. Experimenting with the old throttle I see that the display and motor don't do anything with either plug disconnected. So is the two wire connector the key and voltage display? Do I just need to put a switch on the two wire connector at the controller harness so the 3 wire thumb throttle will work? If the two wire connector is power switch and source of battery voltage for the voltage display, I may put a switch in place of the key along with a different voltage display mounted seperately.


        • Tommycat
          Tommycat commented
          Editing a comment
          I would say your assessment is right on the money. The throttle does indeed just use three wires with a low voltage supply (5vdc regulated) for operation. The other two are full battery power which where switched by the key, and used to 1) power the LED voltage display, 2) ran back down to the controller as an "ignition" or power up circuit. This needs to be armed for the controller to power up and provide the voltage for the electronics operations. (IE: throttle power)
          What is sometimes missed is that the LED display uses the ground wire of the throttle for the return path for operation. Which you would need to run for your new voltage meter. If you have other means of disabling the controller, battery SSR or circuit breaker, battery disconnect etc. You could if desired just tie the two wires together.
          For more information on hall sensor throttles and some wiring diagrams see... This thread...


        • Redorblack Niglebottom
          Redorblack Niglebottom commented
          Editing a comment
          Awesome, as long as the two wire connector doesn't NEED a load to avoid a short that will melt stuff. I have a full kit of JST SM connectors and terminals, so I think for test purposes I'll just make a jumper lead I can plug in and assuming that works, use that as my key until I figure out a more elegant solution. I have a in line amp/voltage etc.. meter I can move to the battery on this trike, I don't use the battery enough (52V 20Ah) to worry about range.. 3 mile commute and with me pedalling more and more I'm finding that after a days riding I've used maybe 1Ah which was for accelerating off stop lights and when "You need me there now?! OK! Be there in a couple of minutes." :) It is fun blasting around at over 30mph, but more exercise when I'm doing most of the work, and I'm desperately trying to get back in shape. This has been key to me using it instead of my car 90% of the time. With the switch from a 7 speed 13-32 freewheel to a 10 speed 11-36 freewheel in the rear and my big 65 tooth chainring from my old Rans Tailwind in the front, I can also get a workout at 33mph pushing at around 60rpm pedal candence or better depending on the gear. With a 53 tooth chainring I guesstimate I was spinning 120-140rpm trying to keep up with the motor. What I really like about bottom bracket drives is keeping myself and the motor in their happy spot, what I'm really liking about this is not snapping components that can't handle the power levels and being stranded 15 miles from home with a broke chain/derailleur etc.. I have newer chains on all my rides except had reused the 1999 chain on this one when I put the hub motor on, heard a clicking while riding in the park one evening, and when I was commuting to work the next day it was still there and I wasn't figuring it out until.... snap, my chain (2.5 chains on a trike...) let loose due to side plate failures and left my chain on the road. Rode the rest of the way to work on the motor and commuted home sans pedal power. Replaced the chains and back in business, but NOT stranded. Unfortunately with lesser hub motors I've been stranded due to smoking the motor and controller. This one handles the hills those couldn't and now I've got the gear range to deal with the hills without the motor if I want.

        Hey how about some pictures. I'll show you mine if you show me yours...……….i'll show you mine anyway

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        This is my KMX. It is not very good past 25 because the handling gets twitchy or to sensitive.

        Here is another view

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        This is my full suspension HP Velotechnik Scorpion. I have been stealing parts from the KMX to finish this one off.

        Click image for larger version

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        I could take some pictures of the controls if you like. I am using a 11-34 cassette with a 60 tooth chainwheel. That 10 spd freewheel you used is a lot taller than the 7spd. How did you shoe horn it between your dropouts.


          Paxtana...are you aware of anybody running a MAC on 72v and if so, how is it working?

          Anybody else know of a MAC on 72v?

          I am considering assembling a 12T MAC in a 24" rim and use a Schwalbe Crazy Bob 24x2.35 tire and running it on the rear of my hardtail bike used for commuting.

          Any info and/or experiences with a MAC on 72 volts (20s battery) would be appreciated...Thanks


            IIRC, Alan over at ert did a build of a bmc at 70v several years ago. Bmc pretty much same thing as Mac.

            ​​​​​here is a video he shot. It's loud as shit, presumably because that's not normally ran like that.


              Thanks Pax...if anybody else has any info or experience they would like to pass along, I sure would appreciate it.

              IMO the MAC is a great motor as long as you don't overheat it and overheating may be my biggest challenge.

              My initial plan to is to increase the cooling by running about 4.5 ounces of distilled water and Motul brand Mocool in the motor to thermally connect the motor to the housing. Been using the Mocool mix for about three months as of this writing no issues...only time will tell if corrosion or other problems occur.


                What is the highest amperage controller anyone has used with their MAC motor?

                There are a boat load of variables like wheel diameter, phase amperage settings vs battery amperage, motor winding 6T/8T/10T/12T etc. etc....just trying to see what others have used successfully without the clutch slipping.

                I have been running a 12 FET 40A Infineon controller with a 12T MAC in a 27.5" rear wheel with a 48v (13S4P) battery with 30Q cells for a couple years without any clutch problems (overheating is another discussion). I have an email in to the manufacturer to see what the phase amperage settings are and I'll report back here if I get an answer.

                The reason I am asking is I'd like to try more amperage for more torque and would like to know if anyone has exceeded the clutch's limits.

                Thanks for any and all input.


                  Finally got an answer on my is a 12 FET Infineon Controller that outputs 40A. The phase amperage settings when shipped are 112A. According to the Grin Tech Motor Simulator, it should have about the same "Thrust" when laced in a rear wheel with a 660 mm outside diameter as my BBSHD with 28F/22R gearing and a rear wheel with a 722 mm diameter.

                  Going to pick up my 24" wheel laced to a MAC hub today and give the configuration described above a try.


                  Speaking of Grin they have a nice wheel building video.


                    A friend had an old Mongoose bike with 24" wheels and I robbed a rim off of his bike.

                    The Nimbus 24" Dominator2 Rim is pretty good and "Kris Holm" brand has some good 24" rims too.

                    Calfee...thanks for chiming in. I don't get on here as much as I should :).



                      One of the 10T's attractions for me is low reported noise.

                      How does the 12T compare with 10T noise-wise?

                      Are the gears still nylon?
                      Last edited by PeteCress; 06-27-2021, 10:52 AM.